Wortmannin Analogs and Methods of Using Same in Combination with Chemotherapeutic Agents

ABSTRACT

Novel wortmannin analogs and their use in inhibiting PI-3-kinase activity in mammals and the treatment or prevention of cancer and tumor formation in a subject are described herein. Preferably, the wortmannin analogs may be administered with other chemotherapeutic agents in the treatment of cancer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application No.60/586,687 filed Jul. 9, 2004 entitled “Wortmannin Analogs and Methodsof Using Same”, incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to wortmannin analogs, and methods ofusing these derivatives alone or in combination with chemotherapeuticagents to inhibit PI-3-kinase activity and to treat certain malignanttumors and other cancers. Wortmannin is a known potent inhibitor ofphosphotidylinositol-3-kinase (PI-3-kinase) and anti-cancer agent.Wortmannin is a naturally occurring compound isolated from culturebroths of the fungus Penicillium wortmannin and has the basic structureshown in U.S. Pat. No. 5,480,906, which is incorporated herein byreference.

SUMMARY OF THE INVENTION

One aspect of the present invention provides novel wortmannin analogsand methods of inhibiting cancer in a subject comprising administeringto a subject a pharmaceutically effective dose of a wortmannin analog.

Another aspect of the present invention provides for a method ofinhibiting PI-3-kinase activity in mammals by administering an effectiveamount of a wortmannin analog.

Another aspect of the present invention provides for use of thecompounds as anti-cancer (anti-tumor) agents, and also forpharmaceutical formulations that includes the compound in combinationwith a pharmaceutically acceptable carrier, recipient or diluent.

A further aspect of the present invention provides for the use ofwortmannin analogs in combination with chemotherapeutic agents to treatcancer.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and advantages of the presentinvention, reference should be had to the following detailed descriptiontaken in connection with the accompanying drawings, in which:

FIG. 1A is a graph of the dose dependency of percent control of HT-29xenograft phospho-Akt by wortmannin analogs of the present invention.FIG. 1B is a graph of the route dependency of the percent control ofxenograft phosphor-Akt by the wortmannin analog PX-866 of the presentinvention.

FIG. 2 is a graph of the concentration of PX-866 (in ng/ml) in mouseplasma following intravenous, intraperitoneal and oral administration.

FIG. 3 is a graph of the concentration of PX-866 and metabolites (inng/ml) in mouse plasma.

FIG. 4 depicts the activity of wortmannin analogs of the presentinvention in the NCl human tumor cell line panel, as measured by IC₅₀.

FIG. 5 is a graph showing the inhibition of HT-29 colon cancer cellphospho-Akt by wortmannin analogs of the present invention.

FIG. 6 is a graph of the mean tumor volume (in mm³) following treatmentwith PX-866, a wortmannin analog of the present invention, alone or incombination with radiation in OvCar-3 human ovarian xenografts.

FIG. 7 is a graph illustrating the potentiation of the antitumoractivity of gefitinib by PX-866.

FIG. 8 is a bar graph illustrating the inhibition of EGFR andphosphor-Akt in A-549 non small cell lung cancer xenografts by gefitiniband PX-866.

FIG. 9 is a bar graph of the percent control of phospho-Akt andphospho-EGFR in A549 lung cancer xenografts with administration ofPX-866 alone (intravenously or orally) or gefitinib alone.

FIG. 10 is a graph depicting the effect of PX-866 on plasma insulin andglucose tolerance.

FIG. 11A is a graph of the mean tumor volume (in mm³) followingtreatment with PX-866, a wortmannin analog of the present invention, andIressa four hours later in A549 small cell lung xenografts. FIG. 11B isa graph of the mean tumor volume (in mm³) following treatment withPX-866, a wortmannin analog of the present invention, in combinationwith Iressa in A549 small cell lung xenografts.

FIG. 12 is a graph of the mean tumor volume (in mm³) following treatmentwith PX-866, a wortmannin analog of the present invention, alone orprior to administration of Iressa in A549 Human Lung Tumor Xenografts.

FIG. 13 is a graph of the mean tumor volume (in mm³) following treatmentwith PX-866, a wortmannin analog of the present invention, alone orprior to administration of Iressa in HT-29 colon cancer cells.

FIG. 14 is a graph of the mean tumor volume (in mm³) following treatmentwith PX-866, a wortmannin analog of the present invention, alone or incombination with Avastin in A-673 thabdomyosarcom xenografts.

FIG. 15 is a bar graph depicting the percent of pAkt-positive hairfollicles in mouse skin following administration of PX-866, Iressa or acombination thereof.

FIG. 16 are wortmannin analogs of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Before the present compositions and methods are described, it is to beunderstood that this invention is not limited to the particularprocesses, compositions, or methodologies described, as these may vary.It is also to be understood that the terminology used in the descriptionis for the purpose of describing the particular versions or embodimentsonly, and is not intended to limit the scope of the present inventionwhich will be limited only by the appended claims.

It must also be noted that as used herein and in the appended claims,the singular forms “a”, “an”, and “the” include plural reference unlessthe context clearly dictates otherwise. Thus, for example, reference toan “fibroblast” is a reference to one or more fibroblasts andequivalents thereof known to those skilled in the art, and so forth.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. Although any methods and materials similar or equivalent tothose described herein can be used in the practice or testing ofembodiments of the present invention, the preferred methods, devices,and materials are now described. All publications mentioned herein areincorporated by reference in their entirety. Nothing herein is to beconstrued as an admission that the invention is not entitled to antedatesuch disclosure by virtue of prior invention.

The methods as described herein for use contemplate prophylactic use aswell as curative use in therapy of an existing condition. As usedherein, the term “about” means plus or minus 10% of the numerical valueof the number with which it is being used. Therefore, about 50% means inthe range of 45%-55%.

“Administering” when used in conjunction with a therapeutic means toadminister a therapeutic systemically or locally, such as directly intoor onto a target tissue, or to administer a therapeutic to a patientwhereby the therapeutic positively impacts the tissue to which it istargeted. Thus, as used herein, the term “administering”, when used inconjunction with a wortmannin analog, can include, but is not limitedto, providing a wortmannin analog into or onto the target tissue;providing a wortmannin analog systemically to a patient by, e.g.,intravenous injection whereby the therapeutic reaches the target tissueor cells. “Administering” a composition may be accomplished byinjection, topical administration, oral administration or by othermethods alone or in combination with other known techniques. Suchcombination techniques include heating, radiation and ultrasound.

As used herein; the term “therapeutic” means an agent utilized to treat,combat, ameliorate, prevent or improve an unwanted condition or diseaseof a patient. In part, embodiments of the present invention are directedto the treatment of cancer and/or the amelioration of the symptoms ofcancer.

A “therapeutically effective amount” or “effective amount” of acomposition is a predetermined amount calculated to achieve the desiredeffect, i.e., inhibiting, blocking, or reversing the activation,migration, or proliferation of cells or to effectively treat cancer orameliorate the symptoms of cancer. A therapeutically effective amount ofa wortmannin analog of this invention is typically an amount such thatwhen it is administered in a physiologically tolerable excipientcomposition, it is sufficient to achieve an effective concentration inthe plasma or serum or an effective local concentration in a targettissue. Effective amounts of compounds of the present invention can bemeasured by improvements in tumor size, tumor burden or symptomsexperienced by the patient being treated. The activity contemplated bythe present methods includes both medical therapeutic and/orprophylactic treatment, as appropriate. The specific dose of a compoundadministered according to this invention to obtain therapeutic and/orprophylactic effects will, of course, be determined by the particularcircumstances surrounding the case, including, for example, the compoundadministered, the route of administration, and the condition beingtreated.

The term “inhibiting” includes the administration of a compound of thepresent invention to prevent the onset of the symptoms, alleviating thesymptoms, or eliminating the disease, condition or disorder.

One aspect of the present invention is wortmannin analogs of thefollowing general formula:

wherein Y is a heteroatom and R1 or R2 are unsaturated alkyl, non-linearalkyl, or substituted alkyl, including a branched alkyl or cyclic alkyl.Preferably, the wortmannin analog corresponds to the chemical formulaselected from the group consisting of the compounds presented in FIG.16. More preferably, R1 or R2 is a disubstituted alkyl, such as PX-866and PX-867.

The biosynthetic production of wortmannin is well known in the art andthe analogs are synthesized from wortmannin. U.S. Pat. No. 5,480,906,which is incorporated herein by reference in its entirety, describestypical synthetic schemes. Typically, wortmannin is produced by thefermentation of any one of a number of previously disclosedmicroorganisms such as Talaromyces wortmannin and Penicilliumwortmannin, Myrothecium roridium, and Fusarium. Following fermentation,wortmannin is extracted and purified via known methods. Preferably,wortmannin is microbially synthesized and isolated in substantially pureform from a fermentation culture) one such fermentation culture isidentified as A24603.1).

Culturing the strain under submerged aerobic conditions in a suitableculture medium until a recoverable amount of wortmannin is producedproduces wortmannin. Wortmannin can be recovered using various isolationand purification procedures understood in the art.

The medium used to grow the culture can be any one of a number of media.For economy in production, optimal yield, and ease of product isolation,however, preferred carbon sources in large-scale fermentation areglucose and soluble starch such as corn starch. Maltose, ribose, xylose,fructose, galactose, mannose, mannitol, potato dextrin, methyl oleate,oils such as soybean oil and the like can also be used.

Preferred nitrogen sources are enzyme-hydrolyzed casein and cottonseedflour, although pepsinized milk, digested soybean meal, fish meal, cornsteep liquor, yeast extract, acid-hydrolyzed casein, beef extract, andthe like can also be used.

Among the nutrient inorganic salts that can be incorporated in theculture media are the customary soluble salts capable of yieldingcalcium, magnesium, sodium, ammonium, chloride, carbonate, sulfate,nitrate, zinc, and like ions. Essential trace elements necessary for thegrowth and development of the organism also should be included in theculture medium. Such trace elements commonly occur as impurities inother substituents of the medium in amounts sufficient to meet thegrowth requirements on the organism.

For production of substantial quantities of wortmannin, submergedaerobic fermentation in stirred bioreactors is preferred. Smallquantities of wortmannin may be obtained by shake-flask culture. Becauseof the time-lag in production commonly associated with inoculation oflarge bioreactors with the spore form of the organism, it is preferableto use vegetative inoculum. The vegetative inoculum is prepared byinoculating a small volume of culture medium with the spore form ormycelial fragments of the organism to obtain a fresh, actively growingculture of the organism. The vegetative inoculum medium can be the sameas that used for larger fermentations, but other media are alsosuitable.

Following its production, wortmannin can be recovered from thefermentation medium by methods used in the art. The wortmannin producedduring fermentation of the A24603.1 organism, for example, occurs mainlyin the broth.

Typically, wortmannin can be recovered from the biomass by a variety oftechniques. A preferred technique involves filtering whole fermentationbroth with a ceramic filter. The filtrate is eluted with an organicsolvent such as ethyl acetate and concentrated. The concentrate issuspended in alcohol until crystallization occurs and the solution isfiltered, washed and dried. For confirmation, the crystalline materialis dissolved in an organic solvent and chromatographed on areverse-phase silica gel absorbent (C₈ or C₁₈). Fractions are eluted inan organic-aqueous buffer such as 60% acetonitrile.

Wortmannin may be further manipulated to arrive at the compounds of thepresent invention. Although the synthesis of particular analogs ofwortmannin are illustrated below, other synthetic schemes common in theart will allow one ordinarily skilled in the art to synthesize compoundsin accordance with the present invention, and the synthetic schemes setforth herein should, in no way, be considered limiting.

For therapeutic treatment of the specified indications, a wortmanninanalog of the present invention may be administered as such, or can becompounded and formulated into pharmaceutical compositions in unitdosage form for parenteral, transdermal, rectal, nasal, localintravenous administration, or, preferably, oral administration. Suchpharmaceutical compositions are prepared in a manner well known in theart and comprise a pharmaceutical carrier and at least one activecompound selected from the group consisting of the term “activecompound”, as used throughout this specification, refers to at least onecompound selected from compounds of the formulas or pharmaceuticallyacceptable salts thereof.

The compounds are effective over a wide dosage range and, for example,dosages per day will normally fall within the range of from 0.001 to 10mg/kg, more usually in the range of from 0.01 to 1 mg/kg. However, itwill be understood that the effective amount administered will bedetermined by the physician in the light of the relevant circumstancesincluding the condition to be treated, the choice of compound to beadministered, and the chosen route of administration, and therefore theabove dosage ranges are not intended to limit the scope of the inventionin any way.

In such a composition, the active compound is known as “activeingredient”. In making the compositions, the active ingredient willusually be mixed with a carrier, or diluted by a carrier, or enclosedwithin a carrier that may be in the form of a capsule, sachet, paper orother container. When the carrier serves as a diluent, it may be asolid, semisolid, or liquid material that acts as a vehicle, excipientof medium for the active ingredient. Thus, the composition can be in theform of tablets, pills, powders, lozenges, sachets, cachets, elixirs,emulsions, solutions, syrups, suspensions, soft and hard gelatincapsules, sterile injectable solutions, and sterile packaged powders.

Some examples of suitable carriers, excipients, and diluents includelactose, dextrose, sucrose, sorbitol, mannitol, starches, gum acacia,calcium phosphate alginates, calcium salicate, microcrystallinecellulose, polyvinylpyrrolidone, cellulose, tragacanth, gelatin, syrup,methyl cellulose, methyl- and propylhydroxybenzoates, talc, magnesiumstearate, water, and mineral oil. The formulations can additionallyinclude lubricating agents, wetting agents, emulsifying and suspendingagents, preserving agents, sweetening agents or flavoring agents. Thecompositions may be formulated so as to provide quick, sustained, ordelayed release of the active ingredient after administration to thepatient by employing procedures well known in the art.

For oral administration, a compound can be admixed with carriers anddiluents, molded into tablets, or enclosed in gelatin capsules. Themixtures can alternatively be dissolved in liquids such as 10% aqueousglucose solution, isotonic saline, sterile water, or the like, andadministered intravenously or by injection.

By “pharmaceutically acceptable”, it is meant the carrier, diluent orexcipient must be compatible with the other ingredients of theformulation and not deleterious to the recipient thereof.

The local delivery of inhibitory amounts of active compound for thetreatment of cancer can be by a variety of techniques that administerthe compound at or near the proliferative site. Examples of localdelivery techniques are not intended to be limiting but to beillustrative of the techniques available. Examples include localdelivery catheters, site specific carriers, implants, direct injection,or direct applications. Local delivery by a catheter allows theadministration of a pharmaceutical agent directly to the proliferativesite.

Local delivery by an implant describes the surgical placement of amatrix that contains the pharmaceutical agent into the proliferativelesion. The implanted matrix releases the pharmaceutical agent bydiffusion, chemical reaction, or solvent activators.

Another example is the delivery of a pharmaceutical agent by polymericendoluminal sealing. This technique uses a catheter to apply a polymericimplant to the interior surface of the lumen. The pharmaceutical agentincorporated into the biodegradable polymer implant is thereby releasedat the surgical site. It is described in PCT WO 90/01969 (Schindler,Aug. 23, 1989).

A final example of local delivery by an implant is by direct injectionof vesicles or microparticulates into the proliferative site. Thesemicroparticulates may be composed of substances such as proteins,lipids, carbohydrates or synthetic polymers. These microparticulateshave the pharmaceutical agent incorporated throughout the microparticleor over the microparticle as a coating. Delivery systems incorporatingmicroparticulates are described in Lange, Science 249: 1527-1533(September, 1990) and Mathiowitz, et al., J. App. Poly. Sci., 26:809(1981).

Local delivery by site specific carriers describes attaching thepharmaceutical agent to a carrier which will direct the drug to theproliferative lesion. Examples of this delivery technique include theuse of carriers such as a protein ligand or a monoclonal antibody.

Local delivery by direct application includes the use of topicalapplications. An example of a local delivery by direct application isapplying the pharmaceutical agent to the arterial tumor or area leftbehind after resection of the tumor.

Formulation of wortmannin analogs is well known in the art as is thefermentation process. Rather than get into exhaustive detail regardingsynthetic scheme or formulation, the present invention relies on theskilled artisan to use those common synthetic and formulation techniquesto synthesize compounds of the following general formula:

wherein Y is a heteroatom and R1 or R2 are unsaturated alkyl, non-linearalkyl, branched alkyl, substituted alkyl or cyclic alkyl. Preferably,the present invention has a chemical formula corresponding to a compoundselected from the group consisting of the compounds presented in FIG.16.

The wortmannin analogs and pharmaceutical compositions containing thesame may be useful in the inhibition of PI-3K and useful in thetreatment and/or prevention of cancer.

Another aspect of the present invention provides for the use ofwortmannin analogs in combination with chemotherapeutic agents in thetreatment and/or prevention of cancer. The wortmannin analogs may beadministered prior to, during or following administration of achemotherapeutic agent. Chemotherapeutic agents include both cytotoxicagents and anti-tumor targeting agents. Exemplary Cytotoxic agentsinclude, but are not limited to, gemcitabine (Gemzar®), paclitaxel(Taxol®), and cisplatin (Platinol®). Exemplary anti-tumor targetingagents include, but are not limited to, gefitinib (Iressa®), erlotinib(Tarceva®), trastuzumab (Herceptin®), cetuximab (Erbitux®) andbevacizumab (Avastin®). In certain embodiments the pharmaceuticalformulation may contain both a wortmannin analog and a chemotherapeuticagent in combination. In other embodiments, the wortmannin analog andthe chemotherapeutic agent may be administered separately, either priorto, substantially simultaneously or after administration of the otheragent.

In another aspect of the present invention, a method of inhibiting PI-3Kby administering a therapeutically effective amount of a wortmanninanalog of the following general formula:

wherein Y is a heteroatom and R1 or R2 are unsaturated alkyl, non-linearalkyl, or substituted alkyl, including a branched alkyl or cyclic alkylis provided. Preferably, the wortmannin analog corresponds to thechemical formula selected from the group consisting of the compoundspresented in FIG. 16. More preferably, R1 or R2 is a disubstitutedalkyl. In one embodiment the wortmannin analog is PX-866 and PX-867. Thewortmannin analog may be administered prior to, substantiallysimultaneously with or after administration of the chemotherapeuticagent.

In another aspect of the present invention, a method of inhibiting PI-3Kby administering a therapeutically effective amount of a wortmanninanalog of the following general formula:

wherein Y is a heteroatom and R1 or R2 are unsaturated alkyl, non-linearalkyl, or substituted alkyl, including a branched alkyl or cyclic alkylin combination with a chemotherapeutic agent is provided. Preferably,121 or R2 of the wortmannin analog is a disubstituted alkyl and thechemotherapeutic agent is selected from the group consisting ofgemcitabine (Gemzar®), paclitaxel (Taxol®), and cisplatin (Platinol®).Exemplary anti-tumor targeting agents include, but are not limited to,gefitinib (Iressa®), erlotinib (Tarceva®), trastuzumab (Herceptin®),cetuximab (Erbitux®) and bevacizumab (Avastin®). In a more preferredembodiment, the method comprises administering PX-866 and gefitinib. Inanother more preferred embodiment, the method comprises administeringPX-867 and gefitinib. The wortmannin analog may be administered priorto, substantially simultaneously with or after administration of thechemotherapeutic agent.

In another aspect of the present invention, a method of treating orpreventing cancer by administering a therapeutically effective amount ofa wortmannin analog of the following general formula:

wherein Y is a heteroatom and R1 or R2 are unsaturated alkyl, non-linearalkyl, or substituted alkyl, including a branched alkyl or cyclic alkylis provided. Preferably, the wortmannin analog corresponds to thechemical formula selected from the group consisting of the compoundspresented in FIG. 16. More preferably, R1 or R2 is a disubstitutedalkyl. In one embodiment the wortmannin analog is PX-866 and PX-867. Thewortmannin analog may be administered prior to, substantiallysimultaneously with or after administration of the chemotherapeuticagent.

In another aspect of the present invention, a method of treating orpreventing cancer by administering a therapeutically effective amount ofa wortmannin analog of the following general formula:

wherein Y is a heteroatom and R1 or R2 are unsaturated alkyl, non-linearalkyl, or substituted alkyl, including a branched alkyl or cyclic alkylin combination with a chemotherapeutic agent is provided. Preferably, R1or R2 of the wortmannin analog is a disubstituted alkyl and thechemotherapeutic agent is selected from the group consisting ofgemcitabine (Gemzar®), paclitaxel (Taxol®), and cisplatin (Platinol®).Exemplary anti-tumor targeting agents include, but are not limited to,gefitinib (Iressa®), erlotinib (Tarceva®), trastuzumab (Herceptin®),cetuximab (Erbitux®) and bevacizumab (Avastin®). In a more preferredembodiment, the method comprises administering PX-866 and gefitinib. Inanother more preferred embodiment, the method comprises administeringPX-867 and gefitinib. The wortmannin analog may be administered priorto, substantially simultaneously with or after administration of thechemotherapeutic agent.

In a further embodiment a compound comprising an active metabolite of awortmannin analog and methods of using the same is provided. In apreferred embodiment, the active metabolite is selected from the groupconsisting of the carbonyl reduced and the carbonyl reduced deacetylatedform of wortmannin analogs. In a preferred embodiment, the activemetabolite is selected from the group consisting of carbonyl reducedPX-866 and carbonyl reduced deacetylated PX-866.

Increased cell survival is a fundamental characteristic of cancer cellsand limits the effectiveness of cancer therapy. An important mechanismfor increased cell survival in many cancers is mediated by thephosphatidylinositol-3-kinase (PtdIns-3-kinase)/Akt (protein kinase B)signaling pathway that is activated by receptor and oncogenic proteintyrosine kinases. Eight mammalian PtdIns-3-kinases are divided into 3main classes; Class I PtdIns-3-kinasesphosphorylate membrane PtdIns togive PtdIns(3,4,5)P₃ which recruits the cytoplasmicserine/threoninekinase Akt by binding to its pleckstrin homology (PH) domain. Membraneassociated Akt is activated by Ser₄₇₃ phosphorylation bymembrane-associated phosphoinositide dependent kinase-1 (PDK1) andThr₃₀₈ phosphorylation by a second incompletely characterized PDK2.Activated Akt detaches from the plasma membrane and moves to thecytoplasm and the nucleus, where it phosphorylates a battery of targetsto prevent the expression of death genes, and induces cell survival.PtdIns-3-kinase activity is increased in human small cell lung cancer,ovarian, head and neck, urinary tract, colon and cervical cancers. Thetumor suppressor protein PTEN (phosphatase and tension homologue deletedon chromosome ten), a dual specificity tyrosine-threonine/PtdIns-3phosphatase, prevents the accumulation of PtdIns(3,4,5)P3 and attenuatesPtdIns-3-kinase signaling (9). PTEN is mutated or deleted in a varietyof human cancers including advanced prostate, endometrial, renal, glial,melanoma, and small cell lung cancers. PX-866 potentiates gefitinibantitumor activity. The protein kinase family has more that 800 humanmembers among which receptor protein tyrosine kinases are frequentlytargets for cancer therapy. They include the epidermal growth factorreceptor (EGFR, ErbB-1, HER1), that when activated by ligand binding toits extracellular domain, homo or heterodimerizes with any of 3 otherfamily members, ErbB-2(HER2), ErbB-3 (HER3) and ErbB-4 (HER4), leadingto autophosphorylation of cytoplasmic C terminal tyrosine residues.These phosphorylations recruit signal transducers leading to activationof signaling pathways that include the Ras-MEK-MAPK pathway, the STATpath way and the PtdIns-3-kinase/Akt survival pathway. The EGFR isamplified or over expressed in a wide range of human cancers where it isthought to play an important role in tumor progression. In non smallcell (nsc) lung cancer EGFR expression is correlated with decreasedpatient survival. A number of small molecule inhibitors of the EGFRkinase as well as EGFR monoclonal antibodies are under development orapproved for clinical use. Gefitinib (ZD 1839, Iressa®) is a smallmolecule EGFR inhibitor that when administered to patients with relapsednsc lung cancer has shown a response rate of 10 to 20% and stabilizedthe disease in another 20 to 30% of patients. However, the addition ofgefitinib to chemotherapy in untreated patients with nsc lung cancer hadno effect on overall survival, time to progression, or response rate. Amajority, but not all, nsc lung cancer patients responding to singleagent gefitinib contain somatic mutations of unknown functionalsignificance in the EGFR tyrosine kinase domain. However, there are alsonsc lung cancer patients that do not have mutated EGFR receptors who mayderive benefit from gefitinib and other EGFR inhibitors. Furthermore,even though activating mutations of the EGFR are rare in humancolorectal cancer and glioblastoma some of these tumors may beresponsive to EGFR inhibitors. A recent study has shown PX-866potentiates gefitinib antitumor activity that gefitinib inhibits cellgrowth and down regulates PtdIns-3-kinase signaling only in nsc lungcancer cell lines with ErbB-3 expression. This is becausePtdIns-3-kinase couples to ErbB-3 leading to PtdIns-3-kinase/Aktsignaling activation only in nsc lung cancer cell lines with either wildtype or mutant EGFR receptor, and ErbB-3. Gefitinib is able to block theassociation of PtdIns-3-kinase with ErbB-3, thus, preventingPtdIns-3-kinase/Akt activation in these cell lines. The central rolePtdIns-3-kinase plays in determining the response to gefitinib suggeststhat an inhibitor of PtdIns-3-kinase may provide a strategy to increasethe antitumor activity of gefitinib in resistant nsc lung cancer tumorsthat do not express ErbB-3. PX-866 is a novel inhibitor ofPtdIns-3-kinase that is currently in advanced preclinical development asan antitumor agent. The A-549 human nsc lung cancer cell line withmutant active Nras that does not express ErbB-3 and is resistant togefitinib was used. It was found that in A-549 tumor xenograftsgefitinib did not inhibit PtdIns-3-kinase/Akt signaling and theadministration of PX-866 either intravenously (iv) or orally (po)markedly potentiated the antitumor activity of gefitinib. The toxicityof long term administration of PX-866 shows that it increases bloodglucose associated with a decrease in insulin sensitivity.

This invention and embodiments illustrating the method and materialsused may be further understood by reference to the followingnon-limiting examples.

Example 1 Acetic acid4-diallylaminomethylene-6-hydroxy-1-α-methoxymethyl-10β,13β-dimethyl-3,7,17-trioxo-1,3,4,7,10,11β,12,13,14α,15,16,17-dodecahydro-2-oxa-cyclopenta[α]phenanthren-11-yl ester (djm2-166)

To a solution of wortmannin (10.7 mg, 25.0 μmol) in CH₂Cl₂ (125 μL) wasadded a freshly prepared 0.2 M stock solution of diallylamine (138 μL,27.5 μmol) in CH₂Cl₂. The reaction mixture was stirred at roomtemperature for 1 h. The solvent and excess amine were removed in vacuo,and the product was purified via chromatography on SiO₂ (hexanes/ethylacetate, 1:9) to give djm2-166 (9.0 mg, 17 μmol, 68%) as an orange oil:[α]_(D)=630 (c 0.0015, CH₂Cl₂, 23 C); IR (KBr) 3391, 1743, 1695, 1685,1622, 1569, 1222, 1111, 1100 cm⁻¹; ^(1H) NMR δ 8.20 (s, 1H), 6.81 (s,1H), 6.06 (dd, 1H, J=7.4, 4.8 Hz), 5.85 (br s, 1H), 5.62 (br, 1H),5.44-5.04 (m, 4H), 4.48 (dd, 1H, J=7.2, 1.9 Hz), 4.05-3.60 (m, 4H), 3.26(s, 3H), 3.27-3.20 (m, 1H), 3.16 (dd, 1H, J=10.9, 7.2 Hz), 3.00-2.90 (m,2H), 2.59 (dd, 1H, J=19.4, 8.6 Hz), 2.40 (dd, 1H, J=14.4, 7.7 Hz),2.35-2.07 (m, 2H), 2.07 (s, 3H), 1.83 (dd, 1H, J=14.4, 4.7 Hz), 1.54 (s,3H), 0.86 (s, 3H); 13C NMR δ 217.0, 178.5, 169.6, 164.8, 156.3, 151.5,139.0, 136.9, 132.2, 131.3, 127.7 (2 C), 119.2, 89.0, 81.9, 73.1, 67.6,59.1, 50.9 (2 C), 48.9, 42.3, 42.2, 37.5, 36.0, 24.6, 22.2, 20.8, 16.1;MS (EI) m/z (rel. intensity) 525 (M⁺, 11), 466 (17), 391 (15), 350 (14),323 (13), 266 (17), 239 (17), 60 (100); HRMS (EI) calculated forC₂₉H₃₅NO₈ 525.2363, found 525.2386.

Example 2

Acetic acid6-hydroxy-1α-methoxymethyl-10β,13β-dimethyl-3,7,17-trioxo-4-pyrrolidin-1-yl-methylene-1,3,4,7,10,11β,12,13,14α,15,16,17-dodecahydro-2-oxa-cyclopenta[a]phenanthren-11-yl(djm2-167).

To a solution of wortmannin (30.0 mg, 70.0 μmol) in CH₂Cl₂ (200 μL) wasadded pyrrolidine (7.0 μL, 84 μmol) in CH₂Cl₂. The reaction mixture wasstirred at room temperature for 1 h. The solvent and excess thiol wereremoved in vacuo and the product was purified by chromatography on SiO₂(hexanes/ethyl acetate 9:1, then 1:1) to give djm2-167 (30.0 mg, 60.6μmol, 86%) as an orange oil: [α]_(D) −390 (c 0.0073, CH₂Cl₂, 23 C); IR(KBr) 3337, 1740, 1684, 1617, 1570, 1261, 1221, 1099, 1018 cm.sup.−1;.sup.1H NMR δ 8.29 (s, 1H), 6.72 (s, 1H), 6.07 (dd, 1H, J=6.9, 4.8 Hz),4.47 (dd, 1H, J=7.0, 1.9 Hz), 3.80-3.70 (m, 2H), 3.25 (s, 3H), 3.25-3.14(m, 2H), 3.02-2.90 (m, 2H), 2.69 (br s, 1H), 2.58 (dd, 1H, J=19.1, 8.4Hz), 2.39 (dd, 1H, J=14.6, 7.8 Hz), 2.32-2.08 (m, 2H), 2.06 (s, 3H),1.99-1.95 (m, 5H), 1.84 (dd, 1H, J=14.5, 4.2 Hz), 1.56 (s, 3H), 0.86 (s,3H); .sup.13C NMR δ 217.5, 178.9, 169.9, 164.9, 153.9, 151.3, 137.6,137.1, 129.2, 89.4, 82.1, 73.3, 67.7, 59.3, 55.2, 49.2 (2 C), 42.6,42.4, 37.8, 36.3, 25.6 (2 C), 24.5, 22.4, 21.0, 16.3; MS (EI) m/z (rel.intensity) 499 (M.sup.+, 1), 439 (2), 365 (7), 167 (35), 149 (100); HRMS(EI) calculated for C₂₇H₃₃NO₈ 499.2206, found 499.2191.

Example 3 Acetic acid4-[(benzylmethylamino)methylene]-6-hydroxy-1α-methoxymethyl-10β,13β-dimethyl-3,7,17-trioxo-1,3,4,7,10,11β,12,13,14α,15,16,17-dodecahydro-2-oxa-cyclopenta[α]phenanthren-11-yl ester (djm2-181)

To a solution of wortmannin (10.7 mg, 25.0 μmol) in of CH₂Cl₂ (125 μL)was added a freshly prepared 0.2 M solution of N-methylbenzylamine (185μL, 37.0 μmol) in CH₂Cl₂. The reaction mixture was stirred at roomtemperature for 2 h. The solvent was removed in vacuo, and the productwas purified by chromatography on SiO₂ (hexanes/ethyl acetate, 1:9) togive djm2-181 (13.3 mg, 24.2 μmol, 97%) as an orange oil: [α]_(D)−835 (c0.0014, CH₂Cl₂, 23 C); IR (neat) 1742, 1685, 1618, 1589, 1575, 1224cm⁻¹; ¹H NMR δ 8.36 (br s, 1H), 7.36-7.27 (m, 5H), 6.60 (bs s, 1H),6.10-6.00 (m, 1H), 4.68-4.63 (m, 1H), 4.53-4.47 (m, 2H), 3.25 (s, 3H),3.25-3.11 (m, 2H), 2.99-2.84 (m, 2H), 2.71 (br, 2H), 2.55 (dd, 1H,J=19.5, 8.9 Hz), 2.38 (dd, 1H, J=14.4, 7.6 Hz), 2.32-2.05 (m, 2H), 2.05(s, 3H), 1.85 (br s, 1H), 1.80 (dd, 1H, J=14.5, 4.7 Hz), 1.52 (s, 3H),0.82 (s, 3H); ¹³C NMR δ 217.3, 178.9, 169.9, 164.7, 158.3, 151.7, 138.8,137.1, 134.9, 129.0 (3 C), 128.6, 128.1 (2 C), 88.7, 82.2, 73.4, 67.9,64.3, 59.4, 49.1, 42.7, 42.5, 37.8 (2 C), 36.3, 25.2, 22.5, 21.1, 16.3;MS (EI) m/z (rel. intensity) 549 (M+, 14), 489 (37), 415 (15), 120 (23),91 (100); HRMS (EI) calculated for C_(31 H35)NO₈ 549.2363, found549.2340.

Example 4

The pharmacodynamics of various wortmannin analogs were tested. Inparticular, the effect of dose of PX-866, PX-867 and PX-881 was measuredon inhibition of HT-29 xenograft phosphor-Akt. FIG. 1A illustrates thatinhibition was increased as the dose of the wortmannin analog wasincreased. PX-866 appeared to exhibit the greatest inhibitory activity.The effect of the route of administration on the inhibitory activity ofPX-866 over time was also measured. PX-866 was administeredintraperitoneal, intravenously and orally. As shown in FIG. 1B, notably,the oral formulation of PX-866 appeared to provide more consistentinhibition over a longer period of time.

The pharmacokinetics of intravenous, intraperitoneal and oraladministration of PX-866 in vivo was measured and is depicted in FIG. 2.Based on the foregoing it appears that the half-life of PX-866 is about16 hours.

The metabolism of PX-866 following oral administration was observed.Generally, PX-866 is metabolized into a carbonyl reduced and carbonylreduced deacetylated metabolites, as depicted below.

As shown in FIG. 3, the most abundant component is PX-866, followed bythe carbonyl reduced metabolite, and then the carbonyl reduced,deacetylated metabolite, however following about 40 minutes atadministration it appears that the carbonyl reduced PX-866 is furthermetabolized to the carbonyl reduced, deacetylated metabolite. Based uponthe foregoing, the T½ of the major metabolite is about at least 3 hours.

Example 5

The activity of wortmannin analogs in the NCl human tumor cell linepanel was measured. Specifically, the activity of wortmannin, PX-889,PX-868, PX-866 and PX-881 was measured in leukemia, NSC lung, colon,CNS, melanoma, ovarian, renal, prostate and breast cancer cell lines asmeasured by IC50. Results are depicted in FIG. 4.

Example 6

The inhibition of HT-29 colon cancer call phospho-Akt, as measured bypercent control, was measured by administration of PX-866 and PX-867.Results are depicted in FIG. 5.

Example 7

The antitumor activity of wortmannin analogs was measured. As shown inTable 1, below, the analogs exhibited antitumor activity againstovarian, colon and lung derived tumors in vivo.

TABLE 1 Initial tumor Growth Log₁₀ vol T/C^(a) % Delay cell Tumor (mm³)Compound mg/kg/day Route Schedule (day) (day) kill p OvCaR-3 120wortmannin 0.75 ip Q1D × 9 47 (40) 5 0.5 * ovarian 120 PX-866 8 ip Q1D ×9 30 (40) 12 1.2 * 120 PX-867 13 ip Q1D × 9 41 (40) 6 0.6 * 120 PX-88112 ip Q1D × 9 52 (40) 8 0.8 * HT-29 colon 180 wortmannin 0.75 ip Q1D × 936 (16) 5 0.3 * 170 PX-866 12 ip Q1D × 9 39 (16) 6 0.4 * 170 PX-867 13ip Q1D × 9 80 (16) 0 0 170 PX-881 12 ip Q1D × 9 62 (16) 2 0.2 A-549 lung65 PX-866 6 ip Q1D × 9 62 (32) 4 0.2 65 PX-866 9 ip Q1D × 9 26 (32) 80.4 * 60 PX-866 12 iv Q1D × 9 45 (21) 5 0.7 * 60 PX-866 4 po Q1D × 9 47(21) 6 0.9 * ^(a)T/C = optimal test/control as % and the day inparenthesis; p < 0.05 compared to non drug treated control tumor growthrate

Example 8

The antitumor activity of radiation alone, PX-866 alone or incombination with radiation was measured in OvCar-3 human ovarianxenografts in mice, as show in FIG. 6. Radiation was administered dailyfor 5 days and compared to administration of PX-866 at 8 and 12.5 mg/kgIP daily for 5 days or in combination with radiation. Results weremeasured in terms of mean tumor volume.

Example 9

The antitumor activity of various cytotoxic drugs alone or incombination with PX-866 was measured. Cytotoxic agents includedgemcitabine, taxol and cisplatin. As shown in Table 2, below, PX-866significantly increased the percent to tumor growth inhibition and delayin growth over treatment with the cytotoxic agents alone in pancreatic,ovarian, lung and colon cancer cell lines.

TABLE 2 Alone Combined Growth log Growth log Size Dose delay cell delaycell Tumor mm³ Drug Route mg/kg Schedule TGI % days kill TGI % days killP - - - 75 gemcitabine ip 150 Q3D × 3 38 7 0.2 anc-1 PX-866 iv 15 Q3D ×3 16 4 0.1 49 8 0.2 pancreatic PX-866 po 5 Q3D × 3 14 0 0 60 19 0.5OvCar-3 110 taxol ip 12 Q2D × 5 58 13 1.0 ovarian PX-866 iv 12 Q2D × 558 12 0.9 83 20 1.5 PX-866 po 4 Q2D × 5 53 11 0.82 87 34 2.6 A-549 300cisplatin ip 1 QD × 5 16 1 0.1 lung PX-866 ip 6 QD × 5 27 3 0.30 58 101.0 HT-29 150 cisplatin ip 2.5 Q2D × 3 11 0 0 colon PX-866 iv 10 Q2D × 311 0 0.3 56 6 0.5 PX-866 po 2.5 Q2D × 3 29 1 0.1 63 8 0.7 TGI (tumorgrowth inhibition) = 100 − T/C %

Example 10

Materials and Methods. Compounds. PX-866 (acetic acid(1S,4E,10R,11R,13S,14R)₄₄-diallylaminomethylene-6-hydroxy-1-methoxymethyl-10,13-dimethyl-3,7,17-trioxo-1,3,4,7,10,11,12,13,14,15,16,17-dodecahydro-2-oxa-cyclopenta[a]phenanthren-11-ylester) was synthesized as previously described (21). For IVadministration to mice PX-866 was dissolved at 10 mg/ml in 5% ethanol in0.9% NaCl, and for po administration at 5 mg/ml in 5% ethanol in water.Gefitinib was obtained from Astra Zeneca (Macclesfield, UK) andsuspended at 7.5 mg/ml in 0.1% Tween 20 in water for po administration.Rabbit purified anti-phosphoSer473-Akt antibody, anti-Akt antibody,antiphospho Tyr1086-EGF-receptor antibody and anti-EGFR antibody wereobtained from Cell Signaling Technology (Beverly, Mass.). Humanrecombinant p110α/p85α, p110β/p85α, p120 (and p110*/p85αPtdIns-3-kinases were obtained from Upstate (Charlottesville, Va.).Metformin hydrochloride was obtained from Spectrum Chemical (Gardena,Calif.), pioglitazone hydrochloride and recombinant human insulin fromSigma Chemical (St. Louis).

Cells. A-549 non small cell lung cancer cells were obtained from theAmerican Tissue Type Collection (Rockville, Md.). The cells were grownin humidified 95% air, 5% CO2 at 37° C. in Dulbecco=s modified Eagle=smedium (DMEM) supplemented with 10% fetal bovine serum (fbs). All celllines were tested to be mycoplasma free using a PCR ELISA kit (RocheDiagnostics Inc., Indianapolis, Ind.).

Measurement of PtdIns-3-kinase. The ability of PX-866 to inhibitrecombinant bovine p110α/p85α and recombinant human p110β/p85α, p120(andp110*/p85α was measured by the [32 P](-ATP dependent phosphorylation ofPtdIns as described by Stirdivant et al (22). Inhibition of cellularPtdIns-3-kinase was measured as the ratio of phosphoSer473-Akt to totalAkt measured by Western blotting, as previously described.

Antitumor Studies. Approximately 107 A-549 nsc lung cancer cells in logcell growth were injected subcutaneously in 0.2 ml phosphate bufferedsaline into the flanks of severe combined immunodeficient (scid) mice.When the tumors reached 100 or 600 mm3 the mice were stratified intogroups of 8 animals having approximately equal mean tumor volumes anddrug administration was started. Dosing was every other day withgefitinib at 75 mg/kg po; PX-866 at 4, 9 or 12 mg/kg iv; PX-866 at 1,2.5 and 3 mg/kg po, or PX-866 administered 4 hr before gefitinib.Animals were weighed weekly and tumor diameters were measured twiceweekly at right angles (d short and d long) with electronic calipers andtumor volumes calculated by the formula volume=(dshort)2×(dlong))2. Whenthe tumor reached 2,000 mm3 or more, or became necrotic the animals wereeuthanized.

Pharmacodynamic Studies. 10⁷ A-549 nsc lung cancer cells were injectedsubcutaneously into the flanks of male scid mice and allowed to grow toapproximately 300 mm3. Mice were administered PX-866 12 mg/kg iv, 3mg/kg po and gefitinib 75 g/kg po, every other day for 5 days. Tumorswere removed 24 hr after the last dose and immediately frozen in liquidN2. For assay, the tumors were homogenized in 50 mM HEPES buffer, pH7.5, 50 mM NaCl, 1% Nonidet P40 and 0.25% sodium deoxycholate andWestern blotting performed using anti-phosphoSer473-Akt and anti Aktantibodies. Tumor Akt activity was expressed as the ratio ofphospho-Ser473-Akt to total Akt.

Toxicity Studies. Male scid mice were administered PX-866 at 10 mg/kgiv, or 3 and 1.5 mg/kg po, every other day for 14 doses. C57B1/6 micewere administered PX-866 at 3 mg/kg po every other day for 15 doses. Themice were killed 24 hr after the last dose and changes in body weight,blood lymphocyte, neutrophil, red blood cell, platelet counts, serumglucose, aspartate amino transferase (AST), and amino alaninetransferase (ALT) were measured.

Glucose Tolerance Studies. Female C5781/6 mice were fasted overnight andadministered a single dose of D(+) glucose (1 mg/kg) as a 0.1 g/mlsolution po. Blood was collected at 0, 10, 20, 30, 60, 90, 120 and 180min and plasma glucose measured using a blood glucose kit (SigmaChemical Co., St Louis, Mo.) to obtain a plasma glucose area under thecurve (AUC 0-180 min). Mice were administered PX-866 10 mg/kg po as asingle dose and glucose administered 4 hours later, or 3 mg/kg PX-866 poevery other day for 20 doses and glucose administered 24 hours and 8days after the last dose. Metformin was administered at 250 mg/kg podaily for 5 days (24) and 10 mg/kg pioglitazone ip daily for 7 days (25)before the glucose administration. Human recombinant insulin wasadministered at 0.075:g/kg ip (26) at the same time as glucoseadministration.

Bone Marrow Colony Formation. After sacrifice, mouse bone marrow wasextracted from each femur and red blood cells lysed with 0.2% hypotonicNaCl followed by the addition of a 1.6% hypertonic NaCl. Approximately20,000 cells were plated in 1 ml of Methocult™ GF M3434 (StemcellTechnologies Inc, Vancouver, BC, Canada) containing 1% methylcellulosein Iscove's Minimum Essential Media, 15% fbs, 1% bovine serum albumin,10:g/ml recombinant human insulin, 200:g/ml human transferrin, 10 mMβ3-mercaptoethanol, 2 mM L-glutamine, 50 ng/ml rm stem cell factor, 10ng/ml recombinant mouse interleukin-3, 10 ng/ml recombinant humaninterleukin-6, and 3 units/ml recombinant erythropoietin. Cells wereplated in triplicate and grown at 37/C and 5% CO2 in a humid environmentfor 14 days before scoring. Colonies (>40 cells/colony) or clusters(3-40 cells) were scored and growth of colony-forming unit granulocyte,erythroid, macrophage, megakaryocyte (CFU-GEMM; burst-formingunits-erythroid (BFU-E), colony-forming units granulocyte macrophage(CFU-GM), assessed using standard criteria. Qualitative observationswere made on background levels of single cells.

Results. PtdIns-3-kinase inhibition. The ability of PX-866 to inhibitrecombinant PtdIns-3-kinases compared to inhibition by wortmannin isshown in Table 3. PX-866 and wortmannin are potent inhibitors of p110α,p120 (and p110* but unlike wortmannin PX-866 is a poor inhibitor ofp110β.

TABLE 3 Inhibition of PtdIns-3-kinases by PX-866 and wortmannin. PX-866wortmannin PtdIns-3-kinase IC₅₀ (nm) IC₅₀ (nm) p110α/p85α 5.5 4.0p110β/p85α >300 0.7 p120γ 9.0 9.0 p110δ/p85α 2.7 4.1

Cell culture studies. PX-866 inhibited phospho-Akt in A-549 human breastcancer cells in media containing 10% fbs with an IC₅₀ of 25 nM.Gefitinib only inhibited phospho-Akt in cells that were serum starvedfor 24 hr and then stimulated with EGF 25 ng/ml but not in media with10% fbs. This suggests that the PtdIns-3-kinase pathway is stimulated bygrowth factors in serum, in addition to EGF. Cell growth inhibitionstudies confirmed previous reports that A-549 cells are resistant togrowth inhibition by gefitinib, with an IC₅₀ of 1.1:M. PX-866 atconcentrations up to 100 nM did not enhance the growth inhibition bygefitinib.

In vivo antitumor studies. Administration of gefitinib at 75 mg/kg poevery other day to mice with 100 mm3 A-549 human nsc lung cancerxenografts inhibited xenograft growth with a T/C of 51% at the end ofthe dosing period (FIG. 7). PX-866 is approximately 4 times more potentas an antitumor agent when given po than given iv, and doses wereadjusted accordingly (Table 4). Female scid mice were implantedsubcutaneously in the flank with 107 A-549 human nsc lung cancer cells.Tumors were allowed to grow to a mean volume of 100 mm before drugtreatment was started every other day for 14 doses. Antitumor activityis expressed as the % volume of the treated tumor/control tumor (TIC %)at the end of the dosing period. There were 8 mice in each group and alldifferences are p<0.01.

TABLE 4 Antitumor Activity of PX-866 in combination with gefitinibPX-844 4 hrs Treatment and Dose before gefitinib Route mg/kg ScheduleTumor T/C % Tumor T/C % gefitinib po 75 QOD × 14 50.8 — PX-866 IV 4 QOD× 14 65.3 20.5 PX-866 IV 9 QOD × 14 31.5 22.3 PX-866 PO 1 QOD × 14 54.840.8 PX-866 PO 2.5 QOD × 14 40.8 18.1

When administered alone to mice with 100 mm3 A-549 tumor xenografts,PX-866 inhibited tumor growth with T/Cs of 31% at 9 mg/kg iv and 41% at2.5 mg/kg po. Preliminary studies showed that PX-866 in combination withgefitinib on an alternating day schedule was more active whenadministered 4 hr before rather than 24 hr after gefitinib (data notshown). When PX-866 was administered 4 hr before gefitinib thecombination gave T/Cs of 22% at 9 mg/kg PX-866 iv and 18% at 2.5 mg/kgPX-866 po. Tumor growth was held stationary for the first half of thetreatment period with PX-866 and then began to slowly increase towardsthe end of the period (FIG. 7). Increased combination antitumor activitywas also seen with very large 600 mm3 A-549 tumor xenografts (FIG. 7B).

Inhibition of tumor EGFR and PtdIns-3-kinase signaling. Administrationof gefitinib 75 mg/kg po to mice with A-549 tumor xenografts every otherday for 5 days inhibited tumor phospho-EGFR by 43% but had nosignificant effect upon tumor phospho-Akt (FIG. 8). PX-866 12 mg/kg ivor 3 mg/kg po, every other day for 5 days, had no significant effectupon tumor phospho-EGFR but inhibited tumor phospho-Akt by 51% and 48%,respectively. The combination of gefitinib and PX-866 inhibited bothtumor phospho-EGFR and tumor phospho-Akt. Similar effects were seen in asecond study as depicted in FIG. 9. Thus, in A-549 tumor xenografts theEGFR and PtdIns-3-kinase pathways appear to function independently andto be selectively inhibited by gefitinib and PX-866, respectively.

Toxicity of long term PX-866 administration. The toxicity of long termadministration of PX-866 to scid mice is summarized in Table 5. Valuesare the mean of 4 mice per group±SE.

TABLE 5 Toxicity of long term PX-866 Administration Treatment ALT ASTglucose WBC Ne LY Group U/l U/l mg/dl K/μl K/μl K/μl Control 52.6 ± 13.6142.9 ± 46.6  46.9 ± 5.1  8.9 ± 1.0  6.9 ± 0.8 1.1 ± 0.2 PX-866 10 mg/Kg35.5 ± 11.7 105.2 ± 19.2  76.2 ± 3.6 14.6 ± 4.2  14.0 ± 2.7 1.8 ± 0.5 ivPX-866 3 mg/Kg 47.6 ± 16.8 152.0 ± 47.2  113.5* ± 23.4 67.8* ± 19.753.6** ± 10.7 5.2 ± 3.9 po PX-866 1.5 mg/Kg 65.6 ± 27.5 140.5 ± 35.2100.1** ± 10.9 16.6* ± 2.4  12.5* ± 1.9 3.1* ± 0.6  po Treatment MO RBCHb Plt Weight change Group K/μl M/μl g/dl K/μl g Control 0.8 ± 0.1 11.0± 0.3 15.4 ± 0.2 1427 ± 60 4.7 ± 0.3 PX-866 10 mg/Kg 1.1 ± 0.2 10.6 ±0.0 14.4 ± 0.1 1390 ± 43 3.9* ± 0.2  iv PX-866 3 mg/Kg 9.2 ± 3.6 10.4 ±0.3 14.7 ± 0.4  1665 ± 227 1.3** ± 0.5  po PX-866 1.5 mg/Kg 1.8* ± 0.2 1030 ± 0.3  14.6 ± 0.3 1221* ± 18  3.9 ± 0.6 po *p = <0.5, **p < 0.01compared to the control value

There was a decreased gain in body weight over the 4 weeks of treatmentwith PX-866 at 10 mg/kg iv and 3 mg/kg po, to 83% and 28% of the controlweight gain, respectively (p 0.05). There was a significant increase inwhite blood cell counts following oral administration of PX-866, dueprimarily to increased blood neutrophil counts. All of the changes inbody weight, plasma glucose and blood cell counts had returned to normalby 9 days after treatment stopped. The decrease in body weight and anincrease in blood glucose were confirmed in two additional studies usingscid mice, but the increase in blood cell counts was less pronounced inthese studies (data not shown).

PX-866 and glucose tolerance. In order to gain further insight into themechanism for the increase in plasma glucose by PX-866, studies wereconducted on insulin levels and on glucose tolerance following an oraldose of 1 g glucose/kg to fasted C57B1/6 mice (FIG. 10). Administrationof PX-866 as a single dose of 10 mg/kg po caused an increase in plasmainsulin levels for up to 5 hr. PX-866 also deceased glucose tolerance inthe mice leading to an increase in plasma glucose, particularly at timepoints after 1 hr after glucose administration where plasma glucose wasdecreasing in non treated mice but increasing in the PX-866 treatedmice. The results expressed as AUC0-180 min for all the glucosetolerance studies are shown in Table 6, below. Values are the mean±SE of4 mice per group.

TABLE 6 Effects of PX-866 on glucose tolerance in mice AUC_(0-180 min)AUC_(0-180 min) Treatment (mg · min · ml⁻¹) (mg · min · ml⁻¹) PX-866 10mg/kg po No Drug 369 ± 25 533 ± 17^(a) Insulin 0.075 μ/kg ip  64 ± 25 64± 5  Metformin 250 mg/kg IP QD × 5 367 ± 46 537 ± 4^(b)  Pioglitazone 10mg/kg ip QD × 7 274 ± 3  340 ± 39^(c) PX-866 3 mg/kg po QOD × 20 520 ±14^(a) 8 day recovery 343 ± 14  Pioglitazone 10 mg/kg IP QD × 7 405 ±26^(d) ^(a)p < 0.05 compared to untreated control ^(b)p < 0.05 comparedto drug treated control without PX-866 ^(c)p < 0.05 compared to PX-866alone ^(d)p < 0.05 compared to chronic PX-866 alone

Treatment with insulin at high doses overcame the increase in plasmaglucose caused by PX-866 and significantly decreased the glucoseAUC_(0-180 min) in both control and PX-866 treated mice. Theantihyperglycemic drug metformin had no effect upon the increase inblood glucose by PX-866, but the hypoglycemic thiazolidinedione drugpioglitazone almost completely blocked the increase (FIG. 10 and Table6). Long term treatment with PX-866 at 9 mg/kg iv every other day for 15doses gave an increase in nonfasting glucose levels (±S.E., n=4) from133.7±16 mg/dl in control mice to 269.4±27.8 mg/dl (p<0.05) in thePX-866 treated mice. The treatment also gave an increase in plasmaglucose AUC_(0-180 min) 24 hr after the last dose of PX-866, but thishad recovered to control values 8 days after the last dose (Table 4).Pioglitazone significantly decreased the glucose AUC₀₋₁₂₀ min 24 hrafter the last dose of long term PX-866 treatment to a value notsignificantly different to control (Table 4).

PX-866 and increased neutrophils. When PX-866 was administered toC57B1/6 mice at 3 mg/kg po every other day for 15 doses there was asignificant increase in neutrophil counts (±S.E., n=4) from 1.2±0.3 K/:1in control mice to 3.7±1.8 K/:1 in PX-866 treated mice (p<0.05), butwith no significant change in any other blood elements. Bone marrowcolony forming units showed no significant change in erythroid lineageCFU-GEMM, BFU-E or CFU-E and a small but significant decrease in myeloidCFU-GM (±S.E., n=4) from 388±52 colonies per 60,000 bone marrow cellsplated in control mice to 168±59 colonies (p<0.05) in the PX-866 treatedmice. At the same time there was an increase in the numbers ofindividual white cells in the cultures from PX-866 treated micesuggestive of altered cell adhesion.

Discussion. Sensitivity of nsc lung cancer cell lines to growthinhibition by gefitinib is associated with inhibition of EGF-stimulatedEGFR autophosphorylation, down regulation of cell surface EGFR, ERK1/2down regulation and inhibition of PtdIns-3-kinase/Akt signaling. ThePtdIns-3-kinase/Akt pathway is a critical pathway for cancer cellsurvival. In a study by Ono et al gefitinib inhibited EGF-inducedPtdIns-3-kinase/Akt signaling, as measured by phospho-Akt levels, innearly all nsc lung cancer cell lines, however, only a few lines (3/11)showed inhibition of phospho-Akt under serum stimulated growthconditions. These results suggest that in many nsc lung cancer celllines factors other than EGF are responsible for the activation ofPtdIns-3-kinase/Akt signaling. Tumor cells with this phenotype may showlimited responsiveness to the cytostatic and/or cytotoxic activities ofEGFR inhibitors. Engelman et al have recently reported that ErbB-3couples EGFR signaling to the activation of Ptdins-3-kinase/Akt, andthat gefitinib inhibits phospho-Akt and cell growth only in nsc lungcancer cell lines expressing EGFR, either wild type or mutant, andErbB-3. However, forced ErbB-3 expression did not render nsc lung cancercells sensitive to gefitinib suggesting that pathways other than EGFRmust activate the Ptdins-3-kinase/Akt signaling in ErbB-3 deficientcells. Other members of the ErbB receptor family may also couple withErbB-3 to activate PtdIns-3-kinase and promote the cancer phenotype. Wereasoned that inhibiting PtdIns-3-kinase could offer a rational strategyto potentiate the antitumor activity of gefitinib in gefitinib resistantnsc lung cancer cell lines.

For the present studies the A-549 nsc lung cancer cell line that isamong the most resistant of nsc lung cancer lines to gefitinib and doesnot express ErbB-3 was chosen. PTEN deficiency can also render cellsresistant to gefitinib growth inhibition presumably through constitutiveactivation of Ptdins-3-kinase/Akt signaling. However, geneticabnormalities of PTEN are relatively rare in lung cancer and A-549cells, as do most nsc lung cancer cell lines, has wild type PTEN andnon-constitutively activated levels of phospho-Akt. To inhibitPtdIns-3-kinase we used PX-866 that has been shown to down regulatetumor phospho-Akt and to exhibit antitumor activity in a number of humantumor xenograft models when administered either intravenously or orally.

It was found that PX-866 administered either iv or po inhibited thegrowth of A-549 nsc lung tumor xenografts in scid mice as effectively asgefitinib. Both agents appeared to be most active when administered longterm giving tumor T/Cs around 50%. However, when PX-866 was administeredtogether with gefitinib, A-549 tumor growth appeared to be heldstationary during the first part of the treatment and increased onlyslightly during the later part of treatment. This was seen with both 100mm₃ tumors and with large advanced 600 mm₃ tumors. Gefitinib failed toinhibit phospho-Akt in A-549 tumor xenografts. In the A-549 cell culturestudies gefitinib also did not inhibit phospho-Akt cells under serumstimulated growth conditions and was only inhibitory in EGF-stimulated,serum deprived A-549 cells. In contrast, PX-866 inhibited phospho-Akt ofA-549 cells under serum simulated growth conditions, and in A-549 humantumor xenografts. Gefitinib inhibited phospho-EGFR in the A-549 humantumor xenografts and PX-866 did not. Thus, PX-866 potentiated theantitumor activity of gefitinib against even very large A-549 tumorxenografts giving complete tumor growth control in the early stages oftreatment. The inhibition of tumor growth was associated with inhibitionof Ptdins-3-kinase/Akt signaling by PX-866 and was not observed withgefitinib alone.

A previous study has reported LY294002, a relatively toxic andnon-specific PtdIns-3-kinase inhibitor with limited potential forclinical development, administered ip potentiates the antitumor activityof gefitinib against small, 6 to 100 mm₃, U87:) EGFR human glioma cellxenografts that coexpress wild type and mutant tumor derived activatedEGFR. In this study neither gefitinib nor LY294002 showed antitumoractivity alone.

The major toxicity of prolonged administration of PX-866 washyperglycemia and decreased glucose tolerance that reversed when drugadministration was stopped. Insulin signals are relayed predominantly bythe PtdIns-3-kinase isoform p110β but also by p110α while growth signalsare relayed by PtdIns-3-kinase p110α. PX-866 is a more potentPtdIns-3-kinase p110α inhibitor than wortmannin but, unlike wortmannin,PX-866 is a poor inhibitor of inhibitor of PtdIns-3-kinase p110β. Acuteadministration of PX-866 to mice decreased glucose tolerance at the sametime that plasma insulin levels were increased suggesting a decrease insensitivity to insulin. This is similar to the phenotype of micedeficient in the Akt2 isoform that includes marked hyperglycemia,hyperinsulinemia and an impaired ability of insulin to lower bloodglucose. In the present study a high dose of insulin was able toovercame the increase in blood glucose caused by PX-866. Metformin, awidely used drug for the treatment of hyperglycemia of type 2 diabetes,lowers blood glucose by stimulating AMP-activated proteinkinase (AMPK)downstream of PtdIns-3-kinase to increase fatty acid oxidation and todecrease triglyceride synthesis, hepatic glucose production and glucoseutilization. AMPK mediates the stimulation of glucose uptake throughtranslocation of the glucose transporter 4 (GLUT-4) to the plasmamembrane. It has been suggested that an AMPK activator such as metforminmight enhance tumor cell survival if used with agents such asPtdIns-3-kinase or Akt inhibitors that impair glucose utilization. Itwas found that metformin had no effect on the decreased glucosetolerance caused by PX-866. It should be noted that a parallel pathwaymediated by the recruitment of the Cbl proto-oncogene to the activatedinsulin receptor also increases glucose uptake by insulin.

In contrast to metformin, the thiazolidinedione hyperglycemic drugpioglitazone reversed the inhibitory effects of both acute and chronicPX-866 administration on glucose tolerance. Thiazolidenediones sensitizethe body to the metabolic effects of insulin by acting as ligands forthe peroxisome proliferator-activated receptor-γ (PPARγ) transcriptionfactor that is present at high levels in adipose tissue. PPARγ alsoinduces differentiation of tumor cells and PPARγ activation bypioglitazone has been reported to inhibit the growth of A-549 nsc lungtumor xenograft in scid mice. While all the details of insulin signalingthrough PtdIns-3-kinase and the effects of glucose lowering drugs suchas metformin and pioglitazone remain to be elucidated, it appears thathyperglycemia caused by PtdIns-3-kinase inhibition by PX-866 isresponsive to insulin and pioglitazone, which could be important for theclinical use of PX-866. The selectivity of PX-866 as an inhibitor ofp110α relative to p110β, unlike wortmannin in which inhibits both p110αand p110β may also explain the more pronounced growth inhibitory effectsof PX-866, and the ability of insulin and pioglitazone to reversePX-866-induced hyperglycia.

The other pharmacological effect of PX-866 administration was anincrease in circulating neutrophils at the same time there is a decreasein bone marrow CFU-GM colony formation The decrease in CFU-GM induced byPX-866 is consistent with the decreased sensitivity to granulocytemacrophage-colony stimulating factor (GM-CSF) observed in bone marrowderived macrophages of p85α−/− knockout mice. The increase incirculating neutrophils by PX-866 may reflect increased mobilization ofprogenitor cells into the peripheral circulation, perhaps associatedwith the decreased cell adhesion as seen in the p85α−/− knockout mice.

In summary, the Ptdins-3-kinase inhibitor PX-866 which shows selectivityfor p110α compared to p110β would appear to potentiate the antitumoractivity of the EGFR inhibitor gefitinib against even large A-549 nsclung cancer xenografts, with substantially complete tumor growth controlin the early stages of treatment. This therapeutic effect of PX-866 wasassociated with inhibition of tumor Akt phosphorylation which was notseen with gefitinib alone. The major toxicity of chronic PX-866 was atarget-related hyperglycemia with a reversible decrease in glucosetolerance due to decreased sensitivity to insulin. The decreased glucosetolerance was insensitive to the AMPK inhibitor metformin but wasreversed by insulin and the PPARγ activator pioglitazone. Long termPX-866 also caused increased neutrophils counts, apparently due tovascular mobilization. Thus, PX-866 by inhibiting PtdIns-3-kinase/Aktsignaling, may have clinical utility in increasing the response to EGFRinhibitors such as gefitinib in patients with nsc lung cancer who do notrespond to therapy with EGFR inhibitors.

Example 11

Further studies of the effects of administration of PX-866 and gefitinibare illustrated below. The present example illustrates the effects ofthe combination of PX-866 and gefitinib (Iressa®) at higher doses. Asshown in FIG. 11, PX-866 was administered 4 hours prior to Iressa®administration (See FIG. 11A) and 24 hours following gefitinibadministration (See FIG. 11B) in A549 small cell lung xenografts. Inaddition, as shown in FIG. 12, PX-866 was also administeredsubstantially simultaneously with gefitinib in A-549 small cell lungxenografts.

Antitumor activity of PX-866 with gefitinib in HT-29 colon cancer wasalso measured. As seen in FIG. 13, PX-866 increased the antitumor effectof gefitinib. Gefitinib was administered at 75 mg/kg po alone, PX-866was administered orally at 2 mg/kg alone or 4 hours prior to gefitinibadministration.

Example 12

The antitumor effect of administration of PX-866 with bevacizumab(Avastin®) was measured. PX-866 was administered at varying dosesintravenously or orally every three days alone or in combination withbevacizumab. As shown in FIG. 14, combination therapy significantlyincreased the antitumor activity of bevacizumab.

Example 13

FIG. 15 depicts PX-866 inhibition of phosphor-Akt in mouse skin alone orin combination with gefitinib.

It is understood that the examples and embodiments described herein arefor illustrative purposes only and that various modifications or changesin light thereof will be suggested to persons skilled in the art and areto be included within the spirit and purview of this application andscope of the appended claims. All publications, patents, and patentapplications cited herein are hereby incorporated by reference in theirentirety for all purposes.

1. A method of treating cancer comprising administering to a subject apharmaceutically effective amount of a compound comprising

wherein Y is a heteroatom and R1 or R2 is an unsaturated alkyl,non-linear alkyl, or substituted alkyl respectively, and achemotherapeutic agent.
 2. The method of claim 1, wherein said R1 or R2is a disubstituted alkyl.
 3. The method of claim 1, wherein saidchemotherapeutic agent is selected from the group consisting of acytotoxic agent and a anti-tumor targeting agent.
 4. The method of claim2, wherein said cytotoxic agent is selected from the group consisting ofgemcitabine, paclitaxel, and cisplatin.
 5. The method of claim 2,wherein said anti-tumor targeting agent is selected from the groupconsisting of gefitinib, erlotinib, trastuzumab, cetuximab andbevacizumab.
 6. The method of claim 1, wherein said compound is:


6. The method of claim 1, wherein said compound is:


7. The method of claim 1, wherein said compound is:


8. The method of claim 1, wherein said compound is administered orally.9. The method of claim 1, wherein said compound is administeredintravenously.
 10. The method of claim 1, wherein said compound isPX-866 and said chemotherapeutic agent is gefitinib.
 11. The method ofclaim 1, wherein said compound is PX-866 and said chemotherapeutic agentis bevacizumab.
 12. The method of claim 1, wherein said compound isPX-867 and said chemotherapeutic agent is gefitinib.
 13. The method ofclaim 1, wherein said compound is PX-867 and said chemotherapeutic agentis bevacizumab.
 14. The method of claim 1, further comprisingadministering an antihyperglycemic agent.
 15. A composition comprising acompound of the formula

wherein Y is a heteroatom and R1 or R2 is an unsaturated alkyl,non-linear alkyl, or substituted alkyl respectively, and achemotherapeutic agent.